Apparatus for temporarily holding logs within cutting-off machines

ABSTRACT

Apparatus for temporarily holding logs within cutting-off machines, characterized in that it comprises two plates ( 60 ) each of which exhibits a plurality of pressers ( 61 ) and an appendix sliding within a guide ( 7 ): the said plates ( 60 ) being associated with an actuator ( 8 ) which drive them, under control, in a substantially straight movement in the direction of the relevant guides ( 7 ) and being disposed in mirror-like and parallel relationship to each other, that is, orthogonally to the logs ( 2 ) to be treated.

The present invention, refers to an apparatus for temporarily holdinglogs within cutting-off machines.

In the following text, the term “logs” is meant to indicate rolls of webmaterial (such as paper) wound up around a support core (for example, atubular cardboard core), to be cut to form rolls of smaller length, thatis, of commercial size.

At present, the production of paper rolls is known to involve cuttingtransversally the logs, produced by a rewinding machine, by using one ormore cutting-off machines.

A cutting-off machine for logs is described in details in the patentIT-1247330.

Essentially, a cutting-off machine of this type comprises:

a plurality of channels or guides into which the logs are discharged andin correspondence of which movable devices, so-called “porters” injargon, are mounted to drive the logs into longitudinal motion bypushing them from behind;

a cutting station, comprising one or more circular blades, rotatingabout axes parallel to those of the logs and fixed on a correspondingmovable support;

means for temporarily holding the logs in said cutting station.

During the normal operation, a log to be cut is disposed, by a relevantporter, in a preset position on the respective guide and blocked in suchposition; then, one of the blades is actuated, that is, it is driveninto a plane orthogonal to the axis of the log, so as to form a shorterroll of preset size therefrom. The length of the roll depends, actually,on the advancement of the porter during the time elapsing between twoconsecutive cuts operated by the blades.

In particular, the means currently used to hold temporarily the logs inthe cutting station, means which are commonly called “pressers”,comprise a plurality of belts associated with corresponding drivingmembers by which the configuration of said pressers can be modified inorder to hold the logs during the cutting steps and release them whenthey have to be moved.

However, the traditional pressers result inadequate to the currentproduction requirements, both in terms of reliability in the long run,especially as far as the operation flexibility is concerned, and ofservice demands.

The main object of the present invention is to overcome the saiddrawbacks.

This result has been achieved, according to the invention, by adoptingthe idea of making a structure having the characteristics described inclaim 1. Further characteristics being set forth in the dependentclaims.

The present invention makes it possible to operate an effective and safehold of the logs during the cutting step, and to ensure, also thanks tothe rigidity of the components that make up the apparatus, the highestreadiness in the response to the commands given by the actuators incharge of the operation of the holding means. Besides, owing to theparticular handling of the pressers, the apparatus can automatically fitto the diameter of the concerned logs, whatever the extent of suchdiameter, without necessitating replacement of parts or components ofthe apparatus, so that the maximum versatility of the latter is thusensured. In addition, an apparatus according to the invention requiresvery little maintenance, is relatively simple to fabricate,cost-effective and reliable even after a prolonged service life.

These and other advantages and characteristics of the invention will bebest understood by anyone skilled in the art from a reading of thefollowing description in conjunction with the attached drawings given asa practical exemplification of the invention, but not to be consideredin a limitative sense, wherein:

FIG. 1 is a schematic side view of an apparatus for feeding logs to acutting station, showing the step at the beginning of a work cycle;

FIG. 2 shows the apparatus of FIG. 1 with a log engaged by clampingmeans and subjected to a cutting operation;

FIG. 3 shows the apparatus of FIG. 1 with another log loaded onto therespective channel of the platform for the sliding of the logs;

FIG. 4 shows the apparatus of FIG. 1 with two logs lined up one afterthe other;

FIG. 5 shows the apparatus of FIG. 4 with the second log having its headsection positioned between the clamping means;

FIG. 6 shows a plan view of the apparatus of FIG. 5;

FIGS. 7 and 8 show the same apparatus in two operating steps that followthe one represented in FIG. 6;

FIG. 9 shows again the same apparatus in a further step, with anotherlog loaded on the platform;

FIGS. 10 and 11 are schematic front views of the configurations taken upby the means for the temporary retention of logs of different diameterin the cutting-off station, respectively;

FIG. 12 is a schematic exploded side view of the retention meansillustrated in FIGS. 10 and 11;

FIG. 13 is a schematic side view of the retention means illustrated inFIGS. 10 and 11;

FIG. 14 is a simplified block diagram of the automatic drive and controlmeans.

The present invention will be described herebelow, with reference to thefigures of the attached drawings, as applied to a device for moving thelogs toward the cutting station, comprising:

a platform (1) with one or more longitudinal channels (10) inside whichthe logs to be cut are disposed;

pusher means (3) acting in correspondence of said platform (1) andintended for acting on the back of the logs (2) to push them, along therespective guide channels (10), toward cutting means (4) disposeddownstream;

clamping means (5) disposed intermediate between said pusher means (3)and said cutting means (4) and intended for engaging the logs (2) whichare pushed along the channels (10) of platform (1) by the pushers (3)and driving them along as far as said cutting means (4).

The said pusher means (3) comprise a bar (30) disposed transverse to thechannels (10) of platform (1) and moved to and from the said clampingmeans (5) by a carriage (31) associated with a corresponding electricmotor (32) (see block diagram of FIG. 14) and mounted for sliding on thetwo long sides of platform (1).

Moreover, the said clamping means (5) are made up of two motor-driven,loop-closed belts (50) disposed opposite to each other, with respect tothe plane (2) on which the logs (2) arrive sliding on the platform (1),so that each belt will always exhibit a length (51) parallel to suchplane: the lengths (51) facing each other (51) of said belts (50) beingspaced apart of an extension substantially equal to the outer diameterof the logs (2).

With reference to the attached drawings, the said cutting means (4)comprise a blade (40) mounted on a support arm (41) which is associatedwith a relevant actuator (400) (see block diagram of FIG. 14) to driveit into motion from and to the logs (2) to be cut.

The operation of the above described apparatus is as follows. The logs(2) are disposed in the channels (10) of platform (1) by automaticloading devices (known to those skilled in the art and, therefore, notto be described herein in details), and the pusher means (3) provide forpushing them toward the belts (50) as far as between the parallellengths (51) of the latter (FIGS. 1 and 2). At this point, each log (2)thus positioned results held between the same belts (50) which, byrotating on respective driving-out rollers, direct the log toward thecutting means (4), as illustrated in FIG. 3, and engage the same log ondiametrically opposite surface portions thereof. The movement of thebelts (50) and thus of logs (2), is intermittent and in synchronism withthe cutting means (4): in correspondence of each dwell, the means (4)are active, so that the logs (2) are cut, whereas during the movement ofbelts (50) the means (4) are inoperative and away from the logs (2). Thespeed and time of operation of the belts (50) are predetermined inrelation to the length of paper rolls (20) to be obtained from thecutting of the logs (2). Once the logs (2) are held between the belts(50), the carriage (31) moves back to take up the relevant initialposition, so that, when disposing further logs (2) in the channels ofplatform (1), these logs can be driven, again by the same pusher means,as far as to dispose the relevant head portions thereof in contact withthe tail sections of the logs (2) previously handed over to the belts(50), as illustrated in FIG. 4. This process is cyclically repeated, asillustrated also in FIGS. 5-9. It thus follows that the feeding of thelogs (2) to the cutting means is performed continuously, that is,without interruptions or empty spaces between consecutive logs, withevident advantages in terms of actual production of the system. Therolls, as they are produced, (20) are pushed by the same logs beingtreated (2) onto a conveyor belt (35) located downstream of the cuttingmeans (4) which provides for moving them away. Possibly disposed betweenthe conveyor belt (35) and the cutting means (4) is a stationaryhorizontal plane (350).

In correspondence of the cutting means (4), there may be provided means(6) intended for temporarily retaining the logs (2) during the cuttingstep, that is, when the cutting means are activated.

The said retention means (6), according to the exemplary embodimentillustrated in the figures of the attached drawings, comprise two plates(60 a, 60 b) each of which exhibits, on one side, a plurality of rigid,substantially semicircular hooks—hereinafter referred to as“pressers”—and, on the opposite side, an appendix (600) slidingly fittedwithin a guide (7) inclined at a predetermined angle to the vertical:the said plates (60 a, 60 b) being associated with an actuator (8)which, under control, drive them into a substantially rectilinear motionin the direction of the respective guides (7), and the same plates beingdisposed in mirror-like and parallel relationship, that is, orthogonallyto the logs (2) to be treated.

The appendixes (600) of said plates (60 a, 60 b) are provided with smallrollers (63) to assist the sliding thereof within the respective guides(7).

Preferably, the said guide (7) is inclined at an angle of 60° to 65° tothe vertical in order to combine, in a way which is deemed to beoptimal, the vertical and horizontal components of the displacement ofeach presser (61), and to allow the apparatus to work as best aspossible whatever the diameter of the logs under treatment, thusresulting extremely versatile.

For example, the said actuator (8) may be an electric motor connected tothe two plates (60 a, 60 b) via a transmission device ofcrank-connecting rod type (80, 81) acting on pivots (83) going throughthe two plates (60 a, 60 b): the said plates (60 a, 60 b) being engagedto a fixed body (100) via corresponding levers (108) each of which, onone side, is hinged to one of the two fixed bodies (100) and, on theother side, is hinged to one of the two plates (60 a, 60 b) above saidpivots (83). The axes of the hinges, connecting the levers (108) withthe plates (60 a, 60 b), being parallel to the pivots (83).

When the cutting means (4) are inoperative and away from logs (2), theplates (60 a, 60 b) are lifted (as shown with solid line in FIG. 12) sothat the logs (2) result free of translating forwards (owing to the pullexerted thereon by the said belts 50). Just before the beginning of thestep for the cutting of logs (2), that is, when these result in cuttingposition, the plates (60 a, 60 b) are lowered (see FIGS. 10 and 11 andthe drawing with dashed lines in FIG. 12) by compressing the surface ofthe logs by means of the hooks (61) which, being approximatelysemicircular and in mirror-like relationship, embrace the logs laterallyand on top as well, thereby retaining them in the preset position. Atthe bottom, the logs (2) rest in part on respective belts (50) and inpart on the plane (350). The lowering and lifting of the plates (60 a,60 b) is caused by the actuator (8) via the array of levers abovementioned.

The controls of pusher means (3), clamping means (5), cutting means (4)and actuator (8), the latter operating the translation of plates (60 a,60 b), are all automated via corresponding programmable electronic meansto which optical, photocell-operated, control means (90) are alsoconnected, the latter being disposed along the operative path of thelogs (2) at known and preset positions. Such-electronic means are knownto those skilled in the industrial automation field and will not,therefore, be described in greater detail.

It is understood that system for moving the logs (2) may be of anysuitable type.

Practically, the construction details may vary in any equivalent way asfar as the shape, dimensions, elements disposition, nature of the usedmaterials are concerned, without nevertheless departing from the scopeof the adopted solution idea and, thereby, remaining within the limitsof the protection granted to the present patent.

1. Apparatus for temporarily holding logs for cutting-off machines,characterized in that it comprises two plates each of which exhibits aplurality of pressers and an appendix sliding within a guide: the saidplates being associated with an actuator which drive them, undercontrol, in a substantially straight movement in the direction of therelevant guides and being disposed in mirror-like and parallelrelationship to each other, that is, orthogonally to the logs to betreated.
 2. Apparatus according to claim 1, characterized in that eachof said guides is inclined at a preset angle to the vertical. 3.Apparatus according to claim 1, characterized in that the said guide isinclined at an angle of 60° to 65° to the vertical.
 4. Apparatusaccording to claim 1, characterized in that the said appendixes of saidplates are provided with small rollers to assist the sliding thereofonto the relevant guides.
 5. Apparatus according to claim 1,characterized in that the said actuator is an electric motor connectedto the two plates via a transmission device of crank-connecting rodtype.
 6. Apparatus for cutting off logs comprising a holding deviceaccording to claim 1, characterized in that said holding device islocated downstream of a device for moving the logs and comprising aplatform with one or more channels inside which logs to be cut aredisposed, and pusher means acting in correspondence of said platform andintended for acting on the back of the logs to push them, alongrespective guide channels, toward cutting means disposed downstream, thesaid logs moving device further comprising clamping means disposedintermediate between said pusher means and said cutting means andintended for engaging the logs which are pushed along the channels ofplatform by the pushers and driving them along as far as said cuttingmeans.
 7. Apparatus according to claim 6, characterized in that the saidpusher means comprise a bar disposed transverse to the channels orplatform and moved to and from the said clamping means by a carriageassociated with a corresponding electric motor and mounted for slidingon the two long sides of platform.
 8. Apparatus according to claim 6,characterized in that the said clamping means comprise motor-driven,loop-closed belts disposed opposite to each other, with respect to theplane on which the logs arrive sliding on the platform, so that eachbelt always exhibits a length parallel to such plane: the lengths facingeach other of said belts being spaced apart of an extensionsubstantially equal to the outer diameter of tie logs.